Head drive IC and liquid discharge apparatus

Abstract

A head drive IC includes: a first waveform input part to which a first waveform signal being used for generation of drive signals is inputted; a second waveform input part to which a second waveform signal different from the first waveform signal and being used for generation of the drive signals is inputted; a switching signal input part to which a switching signal is inputted; and an input switching circuit which performs switching between a state in which both of the input of the first waveform signal and the input of the second waveform signal are allowed, and a state in which the input of the first waveform signal is allowed and the input of the second waveform signal is blocked.

What is claimed is: 
     
       1. A head drive IC, of a liquid discharge head including nozzles and drive elements configured to apply discharge energy to liquid in the nozzles, configured to drive the drive elements, the head drive IC comprising:
 a first waveform input part to which a first waveform signal is inputted, the first waveform signal being used for generation of drive signals driving the drive elements; 
 a second waveform input part to which a second waveform signal is inputted, the second waveform signal being different from the first waveform signal and used for generation of the drive signals; 
 a switching signal input part to which a switching signal is inputted; and 
 an input switching circuit configured to perform switching between a state in which both of the input of the first waveform signal in the first waveform input part and the input of the second waveform signal in the second waveform input part are allowed, and a state in which the input of the first waveform signal in the first waveform input part is allowed and the input of the second waveform signal in the second waveform input part is blocked, according to an input state of the switching signal in the switching signal input part. 
 
     
     
       2. The head drive IC according to  claim 1 ,
 wherein any of a first switching signal and a second switching signal which are different from each other is inputted to the switching signal input part, and 
 the input switching circuit is configured to perform switching such that both of the input of the first waveform signal in the first waveform input part and the input of the second waveform signal in the second waveform input part are allowed in a case of the first switching signal being inputted to the switching signal input part, and that the input of the first waveform signal in the first waveform input part is allowed and the input of the second waveform signal in the second waveform input part is blocked in a case of the second switching signal being inputted to the switching signal input part. 
 
     
     
       3. The head drive IC according to  claim 2 , further comprising:
 a first drive signal generation circuit including a first drive waveform generation circuit configured to generate, from the first waveform signal, a first drive waveform driving the drive elements and a first multiplexer configured to generate a first drive signal driving first drive elements of the drive elements; 
 a second drive signal generation circuit including a second drive waveform generation circuit configured to generate, from the second waveform signal, a second drive waveform driving the drive elements and a second multiplexer configured to generate a second drive signal driving second drive elements, of the drive elements, different from the first drive elements; and 
 a waveform switching circuit connected to the first drive waveform generation circuit, the second drive waveform generation circuit, the first multiplexer, and the second multiplexer and configured to switch, according to the switching signal inputted to the switching signal input part, as to which one of the first drive waveform and the second drive waveform is used to generate the second drive signal in the second drive signal generation circuit, 
 wherein the waveform switching circuit is configured to perform switching such that the second drive signal is generated by using the second drive waveform in the second drive signal generation circuit in the case of the first switching signal being inputted to the switching signal input part, and that the second drive signal is generated by using the first drive waveform in the second drive signal generation circuit in the case of the second switching signal being inputted to the switching signal input part. 
 
     
     
       4. The head drive IC according to  claim 3 , wherein each of the first drive waveform and the second drive waveform includes a plurality of types of drive wave forms driving the drive elements to discharge different amounts of the liquid respectively from the nozzles. 
     
     
       5. The head drive IC according to  claim 3 , wherein the first drive waveform includes predetermined liquid-discharge delay time different from that of the second drive waveform. 
     
     
       6. The head drive IC according to  claim 2 ,
 wherein the input switching circuit includes a switching element configured to switch, according to the switching signal inputted to the switching signal input part, whether the second waveform input part is maintained at a predetermined constant potential, and 
 the switching element is configured to perform switching such that the second waveform signal input part is not maintained at the predetermined constant potential to allow the input of the second waveform signal in the second waveform signal input part in the case of the first switching signal being inputted to the switching signal input part, and that the second waveform signal input part is maintained at the constant potential to block the input of the second waveform signal in the second waveform signal input part in the case of the second switching signal being inputted to the switching signal input part. 
 
     
     
       7. The head drive IC according to  claim 6 ,
 wherein the switching element is a transistor including: 
 a first connection part connected to the second waveform signal input part; 
 a second connection part maintained at the predetermined constant potential; and 
 a third connection part connected to the switching signal input part and disposed between the first connection part and the second connection part, 
 the transistor configured to:
 electrically conduct the first connection part and the second connection part in a case that an electrical potential of the third connection part exceeds a predetermined threshold value which is greater than the predetermined constant potential, and 
 break the conduction between the first connection part and the second connection part in a case that the electrical potential of the third connection part is not more than the threshold value, 
 
 the first switching signal is a signal of the predetermined constant potential, and 
 the second switching signal is a signal of the electrical potential greater than the threshold value. 
 
     
     
       8. A liquid discharge apparatus, comprising:
 the head drive IC as defined in  claim 2 , 
 a liquid discharge head including nozzles and drive elements configured to apply discharge energy to liquid in the nozzles; and 
 a wiring member connected to the head drive IC, 
 wherein the wiring member includes:
 a first waveform trace connected to the first waveform input part and transmitting the first waveform signal; 
 a second waveform trace connected to the second waveform input part and transmitting the second waveform signal; and 
 a first switching trace connected to the switching signal input part and transmitting the first switching signal. 
 
 
     
     
       9. A printer, comprising:
 the liquid discharge apparatus as defined in  claim 8  configured to discharge inks of first color to fourth color as the liquid from the nozzles, 
 wherein, in a case that both of the inputs of the first waveform signal and the second waveform signal are allowed, the drive IC is set to receive:
 a waveform signal to discharge the first and second colors of inks as the first waveform signal; and 
 a waveform signal to discharge the third and fourth colors of inks as the second waveform signal, and 
 
 in a case that the input of the first waveform signal is allowed and the input of the second waveform signal is blocked, the drive IC is set to receive, as the first wave form signal, a waveform signal to discharge the first color of ink and a common waveform signal to discharge the second to fourth colors of inks. 
 
     
     
       10. The printer according to  claim 9 ,
 wherein the first color is black, and 
 the second to fourth colors are yellow, cyan, and magenta. 
 
     
     
       11. The printer according to  claim 10 ,
 wherein the second color is yellow, and 
 the third and fourth colors are cyan and magenta. 
 
     
     
       12. A liquid discharge apparatus, comprising:
 the head drive IC as defined in  claim 2 , 
 a liquid discharge head including nozzles and drive elements configured to apply discharge energy to liquid in the nozzles; and 
 a wiring member connected to the head drive IC, 
 wherein the wiring member includes:
 a first waveform trace connected to the first waveform input part and transmitting the first waveform signal and 
 a second switching trace connected to the switching signal input part and transmitting the second switching signal. 
 
 
     
     
       13. A printer, comprising:
 the liquid discharge apparatus as defined in  claim 12  configured to discharge inks of first color to fourth color as the liquid from the nozzles, 
 wherein the drive IC is set to receive, as the first wave form signal, a waveform signal to discharge the first color of ink and a common waveform signal to discharge the second to fourth colors of inks. 
 
     
     
       14. The printer according to  claim 13 ,
 wherein the first color is black, and 
 the second to fourth colors are yellow, cyan, and magenta. 
 
     
     
       15. The printer according to  claim 14 ,
 wherein the second color is yellow, and 
 the third and fourth colors are cyan and magenta.